Borosilicate glass with high chemical resistance and application thereof

ABSTRACT

The invention discloses a borosilicate glass with high chemical resistance and an application thereof. The borosilicate glass contains 0.25-4.0 wt % of Y2O3 based on the oxide. The borosilicate glass has a high chemical stability, a suitable linear thermal expansion coefficient and is suitable for use in the field of pharmaceutical packaging materials.

FIELD

The present invention relates to a borosilicate glass with high chemicalresistance and applications thereof.

BACKGROUND

In recent years, there are more and more alkaline drugs (such as PH≥10)in the pharmaceutical market. The use of glass containers that do notmeet the requirements of alkali resistance is prone to the phenomenon ofglass detachment. This drug injected into the human body for a long timecan cause serious reactions such as sepsis, etc. Therefore, thepharmaceutical industry has placed a higher demand on the main packagingmaterials, providing a packaging material with significantly improvedalkali-resistant.

Due to its excellent properties, such as high chemical stability, highthermal shock resistance and low coefficient of linear thermalexpansion, borosilicate glass is especially applied in pharmaceuticalpackaging industry (e.g., ampoules and vials for injection), instrumentsand equipment used in chemical industry production and testing, or alloysealing.

When borosilicate glass is used as a primary pharmaceutical packagingmaterial such as ampoules or vials, it is required that the glass hasvery high corrosion resistance to acidic and alkaline media and waterresistance. Moreover, the low coefficient of thermal expansion isadvantageous for ensuring good thermal stability. In addition, thephysical-chemical properties of the glass during further processing areimportant because they have an impact on the properties and applicationsof the final products. To date, known industrial pharmaceutical ampouleshave HGB class 1 water resistance (H, according to YBB00362004-2015),class 1 acid resistance (S, according to YBB00342004-2015) and class 2alkali resistance (L, according to YBB00352004-2015). The representativeof the prior art is transparent glass FIOLAX™. However, the actualexperience shows that in order to ensure the alkali resistance in theproduction process, it is required to develop a glass with a weight lossless than 75 mg/dm² in the laboratory, that is, in the range of class 1alkali resistance, at the same time without damaging other importantglass properties, such as maintaining HGB class 1 water resistance andclass 1 acid resistance, etc.

Although the prior patent documents have described glass with highchemical resistance, the glass still needs to be further improved.Improving its alkali resistance and/or having a suitable coefficient oflinear thermal expansion is particularly required.

DE42306074C1 mentions a silicate glass with high chemical resistance,which has a low content of alkali metal and a low content of Al₂O₃, andcan be fused with tungsten, but have a coefficient of linear thermalexpansion up to 4.5×10⁻⁶/K.

The borosilicate glass disclosed in DE3722130A1 has a high chemicalstability. Although these glasses belong to HGB class 1 water resistantglass, they are still relatively easy to crystallize due to notcontaining K₂O.

The glasses described in DE 19842942A1 and DE19536708C1 have a very highchemical stability, up to HGB class 1 water resistance, class 1 acidresistance, class 1 alkali resistance. However, due to a high content ofZrO₂ in these glasses, the glass is also relatively easy to crystallize.

DETAILED DESCRIPTION

The present invention aims to solve at least one of the technicalproblems to some extent in the related art.

Herein, the present invention provides a borosilicate glass which has aweight loss less than 75 mg/dm² and achieves class 1 alkali resistance(L) while maintaining HGB class 1 water resistance (H) and class 1 acidresistance (S) according to YBB00352004-2015 testing. Further, the glassfiber provided by the present invention has a coefficient of thermalexpansion from 4.6×10⁻⁶/K to 5.2×10⁻⁶/K, and has a high heat resistanceand a good processability.

According to examples of the invention, the borosilicate glass providedherein, based on the oxide, contains from 0.25 to 4.0 wt % Y₂O₃(yttria), preferably in an amount from 0.5 to 3.5 wt %, particularlypreferably from 0.5 to 3.0 wt %. The inventors have found through alarge number of experiments that the addition of Y₂O₃ can greatlyimprove the alkali resistance of the glass. When the content of Y₂O₃ is3.0% by weight, the weight loss of the glass is about 40.0 mg/dm²according to the test method of YBB00352004-2015, and alkali resistanceis greatly improved; but when the content of Y₂O₃ continues to increaseto 4% by weight or more than 4.0% by weight, the glass undergoes phaseseparation and uneven coloration occurs, and the alkali resistance ofthe glass is no longer significantly improved, while the transitiontemperature (T_(g)) and softening temperature (T_(f)) are also improvedsignificantly. In addition, when Y₂O₃ is increased to a certain amount,it mainly provides non-bridge oxygen, which plays a significant role inbreaking network, destroys the glass network structure, makes thestructure loose, and increases the coefficient of linear thermalexpansion of the glass sharply. When the content of Y₂O₃ added is lessthan 0.25%, the alkali resistance of the glass in a boil is 85.25 mg/dm²(>75 mg/dm²), which is a class 2 alkali resistance. When the content ofY₂O₃ is in the above range, the alkali resistance belongs to class 1,which is especially important for ensuring the alkali resistance of theglass in the production process.

In some embodiments, the borosilicate glass provided herein, based onthe oxide, comprises the following components:

SiO₂ 70-77 wt %, B₂O₃ 9.0-12.0 wt %, Al₂O₃3.0-7.0 wt %, Na₂O 5.0-8.0 wt%, K₂O 0-2.0 wt %, Li₂O 0-1.0 wt %, wherein Σ(Na₂O+K₂O+Li₂O) 5.0-9.0 wt%, CaO 0-3.0 wt %, MgO 0-1.0 wt %, BaO 0-2.0 wt %, whereinΣ(CaO+MgO+BaO) 0-5.0 wt %, CeO₂ 0-1.0 wt %, NaCl 0-1.0 wt %, and Y₂O₃0.25-4.0 wt %.

According to examples of the invention, the borosilicate glass providedherein contains from 70 to 77 wt % SiO₂, preferably in an amount from 70to 76 wt %, particularly preferably from 71 to 75.5 wt %. When thecontent of SiO₂ is within this range, the glass properties can beensured under the premise of forming the basic skeleton of the glass. Ahigher content will increase the viscosity of the glass and increase themelting temperature. If the SiO₂ content is further reduced, the acidresistance of the glass will be destroyed.

According to examples of the invention, the borosilicate glass providedherein contains from 9.0 to 12 wt % B₂O₃, preferably in an amount from9.0 to 11.5 wt %, particularly preferably from 9.5 to 11.0 wt %. Thecontent of B₂O₃ plays a crucial role in reducing the coefficient oflinear thermal expansion, processing temperature and meltingtemperature, and improving chemical stability.

In one aspect, B₂O₃ binds the alkali metal ions in the glass more firmlyto the glass structure, and the alkali metal ions released are reducedwhen measuring the water resistance of the glass, and the decrease ofB₂O₃ content can significantly reduce the water resistance. In a furtheraspect, the inventors of the present invention have found through alarge number of experimental studies that as the content of B₂O₃increases, the viscosity of the glass gradually decreases, and thecoefficient of linear thermal expansion gradually decreases. However,when the content is more than 12.0% by weight, the glass may bephase-separated, resulting in uneven internal stress and easy crackingof the glass. The content of B₂O₃ is further increased, and boronvolatilization is more serious, which not only aggravates the erosion ofthe refractory material, causes waste of energy, but also causesfluctuations of the chemical composition of the glass. In addition, thehigher content of B₂O₃ can also adversely affect the acid resistance ofthe glass. Therefore, the content of B₂O₃ should not be too low or toohigh, and it is preferably within the above range.

According to examples of the invention, the borosilicate glass of theinvention contains from 3.0 to 7.0 wt % Al₂O₃, preferably in an amountfrom 3.5 to 6.5 wt %, particularly preferably from 3.8 to 6.5 wt %.Al₂O₃, like B₂O₃, firmly fixes an alkali metal oxide, especially Na₂O,in the glass structure, so an excessively high content will cause anincrease in the melting temperature and the processing temperature. Inaddition, Al₂O₃ has a positive effect against crystallization, andlowering the Al₂O₃ content may increase the crystallization tendencyaccordingly.

According to examples of the present invention, it is important that thecontent of each alkali metal oxide is controlled within a limited rangein the glass of the present invention, and the glass properties can beimproved by optimizing the combination of the contents of the respectivealkali metal oxides. Thus, the glass of the invention contains from 5.0to 8.0 wt % Na₂O, preferably at least 5.5 wt % Na₂O, from 0 to 2.0 wt %K₂O, preferably from 0 to 1.0 wt % K₂O, from 0 to 1.0 wt % Li₂O,preferably from 0 to 0.5 wt % Li₂O; the total amount of alkali metaloxides is from 5.0 to 9.0 wt %, preferably from 6.5 to 8.0 wt %.

The above alkali metal oxides adjust the properties of the glass withinrespective upper limits, for example, the cooperation of three plays animportant role in adjusting the coefficient of linear thermal expansionof the glass, Na₂O and Li₂O decrease the melting temperature andprocessing temperature of glass, K₂O and/or Li₂O play a beneficial rolein reducing glass crystallization, and it is important to maintain abalanced ratio between them. When the respective upper limits areexceeded, the glass has an excessive coefficient of linear thermalexpansion and it is not conducive to reducing costs, while anexcessively low content of the alkali metal oxide results in a too lowcoefficient of linear thermal expansion. Therefore, when the alkalimetal oxide content is limited to the above range, borosilicate glasswhich has a coefficient of linear thermal expansion and a processingtemperature satisfying the requirements can be obtained.

According to examples of the invention, the borosilicate glass of theinvention, contains from 0 to 5.0 wt % alkaline earth metal oxide,preferably in an amount from 0 to 4.0 wt %. Specifically, the content ofCaO is 0-3.0 wt %, preferably 0-2.0 wt %, particularly preferably 0-1.5wt %; the content of MgO is 0-1.0 wt %, preferably 0-0.5 wt %; thecontent of BaO is from 0 to 2.0 wt %, preferably from 0.5 to 1.5 wt %.The above alkaline earth metal oxide changes “the length of the materialof the glass” which is also the processing temperature range of theglass; in addition, alkaline earth metal oxides reduce the hightemperature viscosity of the glass through different networkmodification, improve chemical stability, and reduce the tendency ofcrystallization, which match the viscosity characteristics and otherproperties of the glass with specific production and processingprocesses. In addition, CaO improves acid resistance, and BaO lowers theprocessing temperature without adversely affecting water resistance.Excessive content of the alkaline earth metal oxide can result in anincrease of the coefficient of linear thermal expansion, while too lowcontent can excessively impair the performance of the glass. Preferably,the total content of the alkaline earth metal oxide is at most 5.0 wt %.

According to examples of the present invention, the borosilicate glassof the present invention may contain up to 1.0 wt % CeO₂, and a lowconcentration of CeO₂ is used as a clarifying agent, and a higherconcentration of CeO₂ can prevent the glass from discoloring due toradioactive irradiation. Therefore, the use of such CeO₂-containingglass as a medical packaging material allows the visual inspection ofthe presence of any particulate matter even when placed in a radioactiveirradiation environment. When the concentration of CeO₂ is too high, anintrinsic brownish yellow color which does not meet the demand can begenerated. Further, if the CeO₂ content is too high, the production costof the glass is greatly increased. Therefore, in the present invention,CeO₂ is introduced as a clarifying agent, and the content of CeO₂ ispreferably between 0 and 0.5 wt %.

According to examples of the present invention, the borosilicate glassof the present invention may also contain 0-1 wt % NaCl which is usedmainly as clarifying agent to clarify the glass. In addition to theabove-described CeO₂ and NaCl, those skilled in the art may also useother standard clarifying agents such as CaF₂ and/or sulfates, e.g.,Na₂SO4, and/or nitrates, e.g., NaNO₃. The above clarifying agent is usedin a standard amount, that is, clarification with 0.003-1.0 wt % of thestandard clarifying agent depending on the type and amount of clarifyingagent in the finished glass. According to examples of the presentinvention, in addition to the unavoidable impurities, the glass is freeof As₂O₃ (arsenic trioxide) and Sb₂O₃ (antimony trioxide), which isparticularly advantageous for glass as a main medical packagingmaterial.

According to examples of the invention, the borosilicate glass of theinvention, preferably contains 0.5 to 3.5 wt % Y₂O₃, particularlypreferably in an amount of 0.5 to 3.0 wt %. The inventors have foundthrough a large number of experiments that the addition of Y₂O₃ cangreatly improve the chemical stability, especially alkali resistance ofthe glass. When the content of Y₂O₃ is 3.0% by weight, the weight lossof the glass is about 40.0 mg/dm² according to the test method ofYBB00352004-2015, and alkali resistance is greatly improved; but whenthe content of Y₂O₃ continues to increase to 4% by weight or more than4.0% by weight, the glass undergoes phase separation and unevencoloration occurs, and the alkali resistance of the glass is no longersignificantly improved, while the transition temperature (T_(g)) andsoftening temperature (T_(f)) are also improved significantly. Inaddition, when Y₂O₃ is increased to a certain amount, it mainly providesnon-bridge oxygen, which plays a significant role in breaking network,destroys the glass network structure, makes the structure loose, and thecoefficient of linear thermal expansion of the glass increases sharply.When the content of Y₂O₃ added is less than 0.25%, the alkali resistanceof the glass in a boil is 85.25 mg/dm² (>75 mg/dm²), which is a class 2alkali resistance. When the content of Y2O3 is in the above range, thealkali resistance of the glass obtained belongs to class 1, and thewater resistance and acid resistance also belong to class 1, which isespecially important for ensuring the alkali resistance of the glass inthe production process.

According to examples of the invention, the glass of the invention mayfurther contain 0 to 4.0 wt % at least one of La₂O₃ (lanthanum oxide),ZrO₂ (zirconia), and ZnO (zinc oxide). According to examples of theinvention, the glass of the invention may further contain 0 to 3.0 wt %at least one of La₂O₃ (lanthanum oxide), ZrO₂ (zirconia), and ZnO (zincoxide). In another word, the glass of the invention may furtheroptionally contain 0 to 4.0 wt %, preferably any one of 0-3.0 wt % La₂O₃(lanthanum oxide), ZrO₂ (zirconia), and ZnO (zinc oxide); according toother embodiment, the glass may also optionally contain two of La₂O₃(lanthanum oxide), ZrO₂ (zirconia), and ZnO (zinc oxide), the content ofeach oxide is independently from 0 to 4.0 wt %, preferably from 0 to 3.0wt %. According to other embodiment, the glass may also contain La₂O₃(lanthanum oxide), ZrO₂ (zirconia), and ZnO (zinc oxide) at the sametime, the content of each oxide is independently 0 to 4.0 wt %,preferably 0 to 3.0 wt %, that is, when the glass contains variousoxides of La₂O₃ (lanthanum oxide), ZrO₂ (zirconia), and ZnO (zincoxide), the oxide content are not affected by each other. The glassformed by the combination of Y₂O₃ (yttria) and the oxide ofabove-mentioned content not only does not destroy other productionperformance parameters, but water resistance, acid resistance and alkaliresistance also reaches class 1 at the same time; in addition, La₂O₃(lanthanum oxide), ZrO₂ (zirconia) or ZnO (zinc oxide) is cheaper andmore readily available than Y₂O₃ (yttria), which further reducesproduction costs.

In some embodiments, according examples of the invention, the glass ofthe invention based on oxides contains the following components: SiO₂70-76 wt %, B₂O₃ 9.0-11.5 wt %, Al₂O₃3.5-6.5 wt %, Na₂O 5.0-7.0 wt %,K₂O 0-1.0 wt %, Li₂O 0-1.0 wt %, wherein Σ(Na₂O+K₂O+Li₂O) 6.5-8.0 wt %,CaO 0-2.0 wt %, MgO 0-1.0 wt %, BaO 0-1.5 wt %, wherein Σ(CaO+MgO+BaO)0-5.0 wt %, CeO₂ 0-0.5 wt %, and Y₂O₃ 0.5-3.5 wt %.

In some embodiments, according examples of the invention, the glass ofthe invention based on oxides contains the following components: SiO₂71-75.5 wt %, B₂O₃ 9.1-11.0 wt %, Al₂O₃3.8-6.5 wt %, Na₂O 5.5-7.0 wt %,K₂O 0-1.0 wt %, Li₂O 0-0.5 wt %, wherein Σ(Na₂O+K₂O+Li₂O) 6.0-8.0 wt %,CaO 0-1.5 wt %, MgO 0-0.5 wt %, BaO 0.5-1.5 wt %, wherein Σ(CaO+MgO+BaO)0-4.0 wt %, CeO₂ 0-1.0 wt %, NaCl 0-1.0 wt %, and Y₂O₃ 0.5-3.0 wt %.

According to examples of the invention, the coefficient of linearthermal expansion α20/300 of the glass of the invention is from4.6×10⁻⁶/K to 5.2×10⁻⁶/K, which is similar to that of molybdenum orKOVAR™. Therefore, the glass successfully fusing with molybdenum orKOVAR™, such as an Fe—Co—Ni alloy, can act as sealing glass of suchmetals. In addition, the glass disclosed has good chemical stability,HGB class 1 water resistance, class 1 acid resistance, class 1 alkaliresistance. Due to its high chemical stability, especially excellentalkali resistance and low coefficient of linear thermal expansion, theglass of the invention is particularly suitable for use in packagingmaterials for pharmaceuticals, as well as equipment and glassinstruments in the field of chemical industry production and laboratory.

According to examples of the invention, the suitable melting range andworking range of the glass of the invention results in a reduction inenergy consumption during production.

In another aspect of the invention, the glass provided by the inventionis particularly suitable for use as a pharmaceutical packaging material.

In another aspect of the invention, the glass proposed by the inventionis particularly suitable for use as containers and/or chemical devicesfor chemically erosive liquids.

In another aspect of the invention, the glass proposed by the inventionis particularly suitable for use as a sealing glass of glass-metal, suchas sealing molybdenum metal or KOVAR™ alloy, etc.

In another aspect of the invention, the glass proposed by the inventionis particularly suitable for forming glass fibers used in reinforcingconcrete.

Examples

Embodiments of the invention are described in detail below, examples ofwhich are shown in following tables. The embodiments described in thetables are illustrative and are intended to be illustrative of theinvention and are not to be construed as limiting the invention.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as is commonly understood by one skilled in theart to which this invention belongs. All patents and publicationsreferred to herein are incorporated by reference in their entirety. Theterm “comprise” or “contain” is an open expression, it means comprisingthe contents disclosed herein, but don't exclude other contents. In thepresent invention, all numbers disclosed herein are approximate, whetheror not the words “about” or “about” are used. The value of each numbermay have a difference of less than 10% or a reasonable differenceconsidered by those in the field, such as a difference of 1%, 2%, 3%, 4%or 5%.

Where specific techniques or conditions are not indicated in theexamples, they are carried out according to the techniques or conditionsdescribed in the literature in the art or in accordance with the productspecifications. Any reagents or instruments not indicating manufacturersare commercially available products.

In the examples described below, unless otherwise indicated alltemperatures are set forth in degrees Celsius. The reagents used are allcommercially available or can be prepared by the methods describedherein.

The following abbreviations are used throughout the specification:

In the present invention, the weight percentage (% by weight) of eachcomponent is calculated based on oxides.

mg represents milligram, μg represents microgram, T_(g) representstransition temperature, T_(f) represents expansion softeningtemperature, dm² represents decimeter square, cm² represents centimetersquare, and ° C. represents degrees Celsius;

SiO₂: silica, B₂O₃: boron oxide, Al₂O₃: alumina, Na₂O: sodium oxide,K₂O: potassium oxide, Li₂O: lithium oxide, CaO: calcium oxide, MgO:magnesium oxide, BaO: cerium oxide, CeO₂: cerium oxide, NaCl: sodiumchloride, Y₂O₃: yttrium oxide, La₂O₃: lanthanum oxide, ZrO₂: zirconia,ZnO: zinc oxide.

Chemical resistance can be tested by the following method:

The testing method of water resistance according to YBB00362004-2015: acertain amount of glass granules with specified size was taken into aspecified container, and a certain amount of water was added, thecontainer was heated under specified condition, the water erosion degreeof glass particles was measured and graded with the volume ofhydrochloric acid titration solution (0.01 mol/L) consumed by glassgranules per gram by titrating the leachate. The maximum value of highchemical resistant glass belonging to HGB class 1 water resistance is0.10 mL. The maximum value of high chemical resistant glass belonging toHGB class 2 water resistance is 0.20 mL. The maximum value of highchemical resistant glass belonging to HGB class 3 water resistance is0.85 mL.

The testing method of alkali resistance according to YBB00352004-2015: aglass sample having a total surface area of 10 cm²-15 cm² was etched for3 hours with an equal volume of 0.5 mol/L sodium carbonate and 1.0 mol/Lsodium hydroxide boiling mixed solution. The mass loss per unit surfacearea of the glass sample was determined. Each example in the table givesweight loss in unit of mg/dm². The maximum weight loss of a class 1alkali-resistant glass is 75 mg/dm². The maximum weight loss of a class2 alkali-resistant glass is 175 mg/dm². Glass with a maximum loss morethan 175 mg/dm² belongs to class 3 alkali resistance.

The testing method of acid resistance according to YBB00342004-2015: aglass sample with a total surface area of 100 cm² was etched for 6 hoursin boiling hydrochloric acid solution of 6±0.2 mol/L. The mass loss perunit surface area of the glass sample was determined. Each example inthe table gives weight loss in unit of mg/dm². The maximum weight lossof a class 1 acid-resistant glass is 0.7 mg/dm². The maximum weight lossof a class 2 acid-resistant glass is 1.5 mg/dm². Glass with a maximumloss more than 1.5 mg/dm² belongs to class 3 acid resistance.

The testing method of coefficient of linear thermal expansion (α)according to YBB00202003-2015: a glass block was cut into a glass stripof length×width×height=25×6×6 (error±0.1 mm) using the micro-controlledinner circular cutting machine (Northwest Machinery Co., Ltd.J5085-1/ZF), then α(20; 300)[10⁻⁶/K], transition temperature T_(g) andexpansion softening temperature T_(f) of the glass strip were determinedby a thermal dilatometer (Netzsch DIL 402 PC).

Processing temperature (VA): Orton RSV-1600 rotary high temperatureviscometer was used, the condition is the weight of quenched glasssample≥the weight of turn high temperature viscosity glass sample, andthe corresponding viscosity is 10⁻⁴ dPa·S.

Tables 1-3 give the composition (weight percent, % by weight or wt %,based on oxide) of different glasses of examples of the invention andimportant performance parameters thereof, including: coefficient oflinear thermal expansion α (20;300) (unit: 10⁻⁶/K), transitiontemperature Tg (unit: ° C.), softening temperature T_(f) (unit: ° C.),water resistance H (unit: mL), acid resistance S (unit: mg/dm²), alkaliresistance (unit: mg/dm²); processing temperature VA (unit: ° C.);wherein n.d. means not determined.

TABLE 1 Composition of glass (weight percent, % by weight or wt %, basedon oxides) and main properties Number Components A1 A2 A3 A4 A5 A6 A7 A8SiO₂ 73.19 73.73 75.53 74.01 75.61 75.80 73.53 73.49 B₂O₃ 10.64 10.719.91 11.00 9.37 9.94 10.41 10.71 Al₂O₃ 5.59 5.63 4.84 4.83 4.84 4.056.42 5.63 CaO 1.32 1.33 0.44 0.89 0.89 0.89 0.66 1.33 MgO 0.00 0.00 0.320.32 0.32 0.32 0.16 0.00 BaO 0.60 0.61 1.21 1.21 1.21 1.22 0.60 0.61Na₂O 6.56 6.60 5.88 5.87 5.89 5.90 6.83 6.85 K₂O 0.37 0.37 0.74 0.740.75 0.75 0.37 0.37 Li₂O 0.12 0.12 0.24 0.24 0.24 0.24 0.12 0.12 CeO₂0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 NaCl 0.30 0.30 0.30 0.30 0.300.30 0.30 0.30 Y₂O₃ 0.25 0.50 0.50 0.50 0.50 0.50 0.50 0.50 La₂O₃ 0.98 —— — — — — — ZrO₂ — — — — — — — — ZnO — — — — — — — — Coefficient oflinear 5.01 4.98 4.63 4.71 4.72 4.61 4.90 4.86 thermal expansion(×10⁻⁶/K) T_(g) (° C.) 584.3 583.3 572.2 573.7 576.3 576.5 575.4 585.6T_(f) (° C.) 652.1 647.2 640.9 645.0 642.9 644.2 640.3 652.1 H (mL) 0.030.02 0.02 0.02 0.03 0.02 0.03 0.03 S (mg/dm²) 0.41 0.53 0.45 0.62 0.510.37 0.56 0.51 L (mg/dm²) 63.03 72.00 62.31 65.02 64.23 68.07 68.4969.56 V_(A) (° C.) n.d. 1246 n.d. n.d. n.d. n.d. n.d. n.d.

TABLE 2 Composition of glass (weight percent, % by weight or wt %, basedon oxides) and main properties Number Components A9 A10 A11 A12 A13 A14A15 A16 SiO₂ 73.37 72.65 71.95 71.61 71.37 73.35 71.88 73.43 B₂O₃ 10.6610.56 10.46 10.41 10.40 9.62 10.68 9.10 Al₂O₃ 5.61 5.55 5.50 5.47 5.474.70 4.69 4.70 CaO 1.32 1.31 1.30 1.29 1.29 0.43 0.86 0.86 MgO 0.00 0.000.00 0.00 0.00 0.31 0.31 0.31 BaO 0.60 0.60 0.59 0.59 0.59 1.18 1.181.18 Na₂O 6.57 6.51 6.44 6.41 6.65 5.71 5.70 5.72 K₂O 0.37 0.37 0.360.36 0.36 0.72 0.72 0.72 Li₂O 0.12 0.12 0.12 0.11 0.11 0.23 0.23 0.23CeO₂ 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 NaCl 0.30 0.29 0.29 0.290.29 0.29 0.29 0.29 Y₂O₃ 0.99 1.95 2.90 3.37 0.48 0.48 0.48 0.48 La₂O₃ —— — — 0.96 0.96 0.96 0.96 ZrO₂ — — — — 0.96 0.96 0.96 0.96 ZnO — — — —0.96 0.96 0.96 0.96 Linear thermal 5.07 5.00 5.11 4.94 5.04 4.81 4.684.71 expansion coefficient (×10⁻⁶/K) T_(g) (° C.) 584.3 586.9 593.8594.9 586.0 574.8 576.7 583.0 T_(f) (° C.) 644.5 654.9 662.0 659.1 660.2647.2 648.7 659.0 H (mL) 0.02 0.03 0.03 0.03 0.03 0.02 0.03 0.03 S(mg/dm²) 0.57 0.53 0.63 0.65 0.52 0.57 0.56 0.41 L (mg/dm²) 61.04 55.8339.78 58.18 56.20 51.44 53.09 47.12 V_(A) (° C.) n.d. n.d. n.d. n.d.n.d. n.d. n.d. n.d.

TABLE 3 Composition of glass (weight percent, % by weight or wt %, basedon oxides) and main properties Number Components A17 A18 A19 A20 A21 A22A23 A24 A25 SiO₂ 73.62 71.41 73.19 73.19 73.37 72.65 71.95 71.95 70.59B₂O₃ 9.66 10.11 10.64 10.64 10.66 10.56 10.46 10.46 10.26 Al₂O₃ 3.936.23 5.59 5.59 5.61 5.55 5.50 5.50 5.39 CaO 0.86 0.64 1.32 1.32 1.321.31 1.30 1.30 1.27 MgO 0.31 0.15 0.00 0.00 0.00 0.00 0.00 0.00 0.00 BaO1.18 0.59 0.60 0.60 0.60 0.60 0.59 0.59 0.58 Na₂O 5.73 6.63 6.56 6.566.57 6.51 6.44 6.44 6.32 K₂O 0.73 0.36 0.37 0.37 0.37 0.37 0.36 0.360.36 Li₂O 0.23 0.11 0.12 0.12 0.12 0.12 0.12 0.12 0.11 CeO₂ 0.10 0.100.10 0.10 0.10 0.10 0.10 0.10 0.09 NaCl 0.29 0.29 0.30 0.30 0.30 0.290.29 0.29 0.28 Y₂O₃ 0.48 0.48 0.25 0.25 0.49 0.98 1.93 1.93 0.95 La₂O₃0.96 0.96 — — — 0.98 0.97 — — ZrO₂ 0.96 0.96 0.98 — 0.49 — — 0.97 3.80ZnO 0.96 0.96 — 0.98 — — — — — Linear thermal 4.82 5.06 4.87 4.84 4.975.15 5.04 4.92 4.89 expansion coefficient (×10⁻⁶/K) T_(g) (° C.) 581.4580.3 587.4 578.2 581.3 584.1 589.0 589.9 591.6 T_(f) (° C.) 652.7 638.7656.1 642.9 642.1 643.6 656.2 652.4 661.2 H (mL) 0.02 0.02 0.03 0.020.03 0.02 0.02 0.03 0.02 S (mg/dm²) 0.35 0.54 0.43 0.48 0.45 0.53 0.620.61 0.59 L (mg/dm²) 59.40 54.68 62.55 68.27 54.76 57.76 39.16 40.1041.23 V_(A) (° C.) n.d. n.d. n.d. 1236 n.d. n.d. n.d. n.d. n.d.

It's clearly known according to the embodiments shown in tables 1-3 ofthe invention that:

The glass of the invention has good chemical stability, specifically,when the water resistance is tested at 98° C. according toYBB00362004-2015, the degree of water erosion of glass is measured byvolume of hydrochloric acid titration solution (0.01 mol/L) consumed byglass particles per gram, and the value is at most 0.03 ml. Thisindicates that the glass of the present invention is excellent in waterresistance which belongs to class 1 water resistance.

When the alkali resistance is tested according to YBB00352004-2015, themass loss per unit surface area of the glass test sample is less than 75mg/dm². This indicates that the glass of the present invention isexcellent in alkali resistance which belongs to alkali-resistant class1.

When the acid resistance is tested according to YBB00342004-2015, themass loss per unit surface area of the glass test sample is less than0.70 mg/dm². This indicates that the glass of the present invention isalso excellent in acid resistance which belongs to acid-resistantclass 1. Therefore the glass of the invention is 1-1-1 glass, that is,the glass belongs to class 1 in every aspect of the three chemicalresistances.

Thus, the highly chemical resistant glass of the present invention iswell suited for use in medical packaging materials, and use as equipmentfor chemical industry production and laboratory research, and ascontainers for chemically erosive liquid.

The viscosity of the glass in the cooling zone is characterized by theglass transition temperature T_(g), which corresponds to a viscosity ofapproximately 10^(13.4) dPa·s. The suitable transition temperatureobtained by the glass of the invention is advantageous in reducing theenergy consumption in the production process.

The coefficient of linear thermal expansion α20/300 of the glass of theinvention is 4.6×10⁻⁶/K to 5.2×10⁻⁶/K, which is similar to that ofmolybdenum or KOVAR™. Therefore, the glass successfully capable offusing with molybdenum or KOVAR™ can act as sealing glass of suchmetals, and is suitable for use in molten glass/metal seals used inchemically corrosive environments due to the good chemical resistance ofthe glass. One skilled in the art can vary the coefficient of linearthermal expansion by the content of alkali metal oxide.

The glass of the present invention is easily converted into glassfibers. Due to the good chemical resistance of the glass, which leads toan increase in its long-term durability, these glass fibers areextremely suitable for reinforcing concrete parts, and can be used asshort fibers and filaments (production of concrete/glass fibercomposites).

Related person can clearly realize and apply the techniques disclosedherein by making some changes, appropriate alterations or combinationsto the methods without departing from spirit, principles and scope ofthe present disclosure. Skilled in the art can learn from this articleto properly improve the process parameters to implement the preparationmethod. Of particular note is that all similar substitutions andmodifications to the skilled person is obvious, and they are deemed tobe included in the present invention.

1. A borosilicate glass comprising 0.25-4.0 wt % of Y₂O₃ based on oxide.2. The borosilicate glass of claim 1, comprising the followingconstituents based on oxide: SiO₂ 70-77 wt %, B₂O₃ 9.0-12 wt %, Al₂O₃3.0-7.0 wt %, Na₂O 5.0-8.0 wt %, K₂O 0-2.0 wt %, Li₂O 0-1.0 wt %,wherein Σ(Na₂O + K₂O + Li₂O) 5.0-9.0 wt %, CaO 0-3.0 wt %, MgO 0-1.0 wt%, BaO 0-2.0 wt %, wherein Σ(CaO + MgO + BaO) 0-5.0 wt %, CeO₂ 0-1.0 wt%, NaCl 0-1.0 wt %, Y₂O₃ 0.25-4.0 wt %.


3. The borosilicate glass of claim 1, comprising the followingconstituents based on oxide: SiO₂ 70-76 wt %, B₂O₃ 9.0-11.5 wt %, Al₂O₃3.5-6.5 wt %, Na₂O 5.0-7.0 wt %, K₂O 0-1.0 wt %, Li₂O 0-1.0 wt %,wherein Σ(Na₂O + K₂O + Li₂O) 6.5-8.0 wt %, CaO 0-2.0 wt %, MgO 0-1.0 wt%, BaO 0-1.5 wt %, wherein Σ(CaO + MgO + BaO) 0-5.0 wt %, CeO₂ 0-0.5 wt%, Y₂O₃ 0.5-3.5 wt %.


4. The borosilicate glass of claim 1, comprising the followingconstituents based on oxide: SiO₂ 71-75.5 wt %, B₂O₃ 9.1-11.0 wt %,Al₂O₃ 3.8-6.5 wt %, Na₂O 5.5-7.0 wt %, K₂O 0-1.0 wt %, Li₂O 0-0.5 wt %,wherein Σ(Na₂O + K₂O + Li₂O) 6.0-8.0 wt %, CaO 0-1.5 wt %, MgO 0-0.5 wt%, BaO 0.5-1.5 wt %, wherein Σ(CaO + MgO + BaO) 0-4.0 wt %, CeO₂ 0-1.0wt %, NaCl 0-1.0 wt %, Y₂O₃ 0.5-3.0 wt %.


5. The borosilicate glass of claim 1 comprising at least one of La₂O₃,ZrO₂, and ZnO in an amount from 0 to 4.0 wt %.
 6. The borosilicate glassof claim 1 comprising at least one of La₂O₃, ZrO₂, and ZnO in an amountfrom 0 to 3.0 wt %.
 7. The borosilicate glass of claim 1, having acoefficient of linear thermal expansion α_(20/300) from 4.6×10⁻⁶/K to5.2×10⁻⁶/K, a class 1 water resistance according to YBB00362004-2015, aclass 1 acid resistance according to YBB00342004-2015, and/or a class 1alkali resistance according to YBB00352004-2015.
 8. The borosilicateglass of claim 1 wherein the borosilicate glass is free of As₂O₃ and/orSb₂O₃ apart from inevitable impurities.
 9. Use of the borosilicate glassof claim 1 as a packaging material for a pharmaceutical, as a containeror a chemical device for a chemically erosive liquid, as a sealing glassfor an alloy, or for forming a glass fiber.
 10. (canceled) 11.(canceled)
 12. (canceled)
 13. The use of claim 9, wherein the glassfiber is for reinforcing concrete.
 14. The borosilicate glass of claim2, comprising at least one of La₂O₃, ZrO₂, and ZnO in an amount from 0to 4.0 wt %.
 15. The borosilicate glass of claim 4, comprising at leastone of La₂O₃, ZrO₂, and ZnO in an amount from 0 to 4.0 wt %.
 16. Theborosilicate glass of claim 2, comprising at least one of La₂O₃, ZrO₂,and ZnO in an amount from 0 to 3.0 wt %.
 17. The borosilicate glass ofclaim 4, comprising at least one of La₂O₃, ZrO₂, and ZnO in an amountfrom 0 to 3.0 wt %.
 18. The borosilicate glass of claim 2, having acoefficient of linear thermal expansion α_(20/300) from 4.6×10⁻⁶/K to5.2×10⁻⁶/K, a class 1 water resistance according to YBB00362004-2015, aclass 1 acid resistance according to YBB00342004-2015, and/or a class 1alkali resistance according to YBB00352004-2015.
 19. The borosilicateglass of claim 4, having a coefficient of linear thermal expansionα_(20/300) from 4.6×10⁻⁶/K to 5.2×10⁻⁶/K, a class 1 water resistanceaccording to YBB00362004-2015, a class 1 acid resistance according toYBB00342004-2015, and/or a class 1 alkali resistance according toYBB00352004-2015.
 20. The borosilicate glass of claim 2, wherein theborosilicate glass is free of As₂O₃ and/or Sb₂O₃ apart from inevitableimpurities.
 21. The borosilicate glass of claim 4, wherein theborosilicate glass is free of As₂O₃ and/or Sb₂O₃ apart from inevitableimpurities.
 22. Use of the borosilicate glass of claim 2 as a packagingmaterial for a pharmaceutical, as a container or a chemical device for achemically erosive liquid, as a sealing glass for an alloy, or forforming a glass fiber.
 23. Use of the borosilicate glass of claim 4 as apackaging material for a pharmaceutical, as a container or a chemicaldevice for a chemically erosive liquid, as a sealing glass for an alloy,or for forming a glass fiber.